This invention relates in general to a liquid applicator tool, and in particular to a tool for dispensing liquid from a disposable cartridge and for brushing the dispensed liquid onto a surface.
A disposable cartridge containing liquid such as glue, sealant or caulk is usually cylindrical in shape and includes a nozzle at one end and a plunger in the other end. A well known dispensing tool (often called a "caulking gun") uses a trigger operated ratchet mechanism to ratchet the plunger toward the nozzle, thereby forcing liquid out of the nozzle. The rate at which the operator depresses the trigger controls the rate at which the tool dispenses liquid, but liquid may continue to flow after the user releases the trigger until discharge of liquid from the cartridge reduces ratchet pressure on the plunger. Some tools include a lever for releasing ratchet pressure on the plunger so as to stop liquid flow. However after releasing ratchet pressure on the plunger, an operator may have to depress the trigger more than once to build up sufficient pressure to restart liquid flow.
In some applications workmen must brush sealant dispensed from a cartridge onto a surface. For example, spaces between spars in an airplane wing are often used for storing fuel. To prevent leakage of fuel at joints where wing skin sections meet over spars, workmen brush sealant on the joints. Since the sealant consists of components that react together at ambient temperature, about 18.degree. C., the components are premixed and packaged in disposable plastic cartridges and frozen until used. When required, a cartridge is thawed. Workmen have found it difficult to use a dispensing tool and a brush at the same time. Therefore workmen typically find it easier to dispense the sealant from the cartridge into an open container and then apply the sealant with a paint brush dipped into the container. This method of dispensing and applying the sealant is laborious and time-consuming.